The failure to attain direct experience of the truth, and consequently of freedom, is due to man's spiritual ignorance

"Samkara, speaking of the supreme goal of human life, says: 'A man is born not to desire enjoyments in the world of the senses, but to realize the bliss of jivanmukti [liberation while living].' And the Upanishads over and over again emphasize this truth: 'Blessed is he who attains illumination in this very life, for a man not to do so is his greatest calamity.' But in these same scriptures it is pointed out that if a man fails to attain the supreme goal in this life he can attain it in some other life, for he will be given unlimited opportunities, by rebirths to reach the goal of perfection.
The failure to attain direct experience of the truth, and consequently of freedom, is due to man's spiritual ignorance, which is all but universal, and which forms the chief cause of sin and suffering. It can be dispelled by direct knowledge of the ultimate truth obtained through purification of the heart, and through a constant striving for detachment of the soul from worldly desires. By transcending the limitations of the body, the mind and the senses, one may enter the superconscious state."

"As we have intimated, the Vedas, or Srutis (revealed truths), stand
as an absolute authority behind which the orthodox schools cannot go.
In this sense their authority might seem to resemble that of the Holy
Bible in many periods of Christian thought; but in the words of Dr S.
Radhakrishnan, 'The appeal to the Vedas does not evolve any reference
to an extra-philosophical standard. What is dogma to the ordinary man
is experience to the pure of heart.'[1] With the exception of
Buddhism and Jainism, all Indian schools of thought regard the Vedas
as recording the transcendental experience of the first mighty seers
of India. This experience cannot and should not contradict similar
experience in any age or country. Furthermore, it is accessible to
all. For these reasons, all Hindus believe that the Vedas are eternal—
beginningless and endless—and that in them transcendental experience
has had its standard manifestation.

What then of Buddhism and Jainism? Shall we exclude them from the
highest expressions of Indian thought? The fact is that they accept
the authority of revealed knowledge and transcendental experience,
though they deny the authority of the Vedas, particularly of the
ritualistic portions, as a result of certain historical
circumstances. They were born at a time when the spirit of the Vedas
had been lost, when the Hindus held faithfully only to the letter of
the law, and when priestcraft reigned supreme. The yearning to know
the truth of the Self, or Brahman in one's own soul, which is
attained only by the pure at heart, was absent. Buddha, though he
denied the authority of the Vedas, actually impressed their spirit
upon his followers by urging them to live the pure life in order to
free themselves from the burden of sorrow. And he showed the way by
himself attaining nirvana—another name for samadhi, the
transcendental state.

Thus the teachings of Buddha do not contradict the spirit of the
Vedas but are in entire harmony with it; and the same is true of the
teachings of Mahavira, founder of Jainism...

Philosophers differ, however, with respect to the exact nature of
moksa; and the differences make up the substance of Hindu thought.
These are due in part to varying grades of experience in realizing
the transcendental life; and of course they are due above all to the
attempt to express the inexpressible.

In one thing, however, the philosophers all agree. That is, that
spiritual perfection can be attained here and now. 'Man's aim', says
Professor Hiriyanna, 'was no longer represented as the attainment of
perfection in a hypothetical hereafter, but as a continual progress
towards it within the limits of the present life.' Moksa, or the
attainment of freedom from the limitations and sufferings of physical
life, is the supreme aspiration of all Indian philosophy.

Samkara, speaking of the supreme goal of human life, says: 'A man is
born not to desire enjoyments in the world of the senses, but to
realize the bliss of jivanmukti [liberation while living].' And the
Upanishads over and over again emphasize this truth: 'Blessed is he
who attains illumination in this very life, for a man not to do so is
his greatest calamity.' [2] But in these same scriptures it is
pointed out that if a man fails to attain the supreme goal in this
life he can attain it in some other life, for he will be given
unlimited opportunities, by rebirths to reach the goal of perfection.

The failure to attain direct experience of the truth, and
consequently of freedom, is due to man's spiritual ignorance, which
is all but universal, and which forms the chief cause of sin and
suffering. It can be dispelled by direct knowledge of the ultimate
truth obtained through purification of the heart, and through a
constant striving for detachment of the soul from worldly desires. By
transcending the limitations of the body, the mind and the senses,
one may enter the superconscious state.

The methods of attaining this highest state of consciousness are
hearing about, reasoning about, and meditating upon the ultimate
reality. One must first hear about it from the Sruti, or Vedas, and
from the lips of a guru, an illumined teacher. Then one must reason
about it. Finally comes the meditation upon it in order to realize
the truth for oneself. Different schools offer different methods of
attaining the same goal, but all agree in recommending the practice
of yoga, or the exercises prescribed in the art of concentration and
meditation.

To tread he path of philosophy is to seek after truth and follow a
way of life. Before a man sets out on the quest after truth, he must
fulfil certain conditions. Samkara sums them up as follows: First,
there must be discrimination between the real and the unreal. This
statement means, not that a man must posses complete knowledge of
absolute reality, which is attained only after long practice of
meditation, but that he must unfailingly subject the nature of things
to a rigid analysis by discriminating between what is transitory and
what is abiding, or between what is true and what is false. The
second condition is detachment from the selfish enjoyments of life.
The aspirant must learn that the highest good is realized not through
worldly pleasure, but through a continuous search for the infinite,
the enduring joy. This ideal of renunciation must be realized by a
gradual purification of the seeker's heart and mind. A third
condition is that the student must acquire tranquility of mind, self-
control, patience, poise, burning faith in things of the spirit, and
self-surrender. These are called the six treasures of life. The
thirst for moksa, or release, is the fourth condition."